Akitsu Kimoto and Evan Canfield: Pima County Regional Flood Control

Tom Arnold: Tucson Water

BackgroundCity of Tucson/Pima County Water Study

Joint Effort for Sustainable Water Resource Planning Core Elements: Water Supply, Demand Management,

Comprehensive Integrated Planning, Respect for Environment

Understanding Water Use Patterns is basic to address Demand Management, so the study had three focus areas: Construction Pattern Changes and Water Use at a Parcel

Scale Per-Household Water Use Study Per-Capita Water Use Study

Spatial Pattern of Water Use at a Subdivision Scale Subdivision Water Use Study

OutlineObjective: Assess Water Use at a Subdivision

Scale within Tucson Water Service Area.

We evaluated….Spatial patterns of subdivision water useSpatial pattern of household sizeProperty value, area and subdivision water use Variability of water use within an individual

subdivision.

Data Used Spatial Datasets (Pima County GIS library)

Parcel data Subdivision data Tucson Water Service Area boundary Census Block 2010 data

 Tabular Data MAS 2011 (Pima County Assessor’s Office data) Monthly water use data from 2009 and 2010 (Tucson Water)

Parsed Study Dataset Removed parcels with a month of no water use Used parcels with homes built before 2008 (“normal” level of

water demand established) Used subdivisions consisting of 100% single family residences (i.e.

no multi-family residences) Final dataset includes~ 70,000 residential customers in 1,200

subdivisions

Average Household Size (Number of People living in a House – 2010 Census)

Southern and Southwestern Tucson: Larger Household Size

Average Household Monthly Water Use at Subdivision Scale (1 Ccf = 748 gals)

Water UseCcf

< 7.5

7.6 - 10.0

10.1 - 12.5

12.6 - 15.0

15.1 - 17.5

17.6 - 20.0

> 20.1

E I10

W I10N I1

9S

I19

N O

RA

CLE

RD

W AJO HY

E 22ND ST

W INA RD

E SPEEDWAY BL

E BROADWAY BL

S M

ISSI

ON

RD

N SILVERBELL RD

E VALENCIA RD

S K

OLB

RD

S H

OU

GH

TON

RD

W TANGERINE RD

N SW

AN

RD

E GRANT RD

S PA

RK

AV

W I10 FRONTAGE RD

N LA

CA

NA

DA

DR

S 12

TH A

V

S NO

GA

LES HY

S 6T

H A

V

N CA

MPB

ELL

AV

N TH

OR

NYD

ALE

RD

S W

ILM

OT

RD

N C

RAY

CR

OFT

RD

W MOORE RD

E SUNRISE DR

N LA

CH

OLL

A B

L

E OLD SPANISH TR

E TANQUE VERDE RD

W VALENCIA RD

W IRVINGTON RD

E AJO WYW BOPP RD

E 36TH ST

E DREXEL RD

N K

OLB

RD

E 29TH ST

E 6TH ST

E CAT

ALINA H

Y

S KINNEY RD

E GOLF LINKS RD

S SW

AN

RD

N SO

LDIE

R T

RE IRVINGTON RD

N 6T

H A

V

W ORANGE GROVE RD

W STARR PASS BL

E 5TH ST

N KINNEY RD

N 1S

T AV

W SUNSET RD

S FR

EEM

AN

RD

N W

AD

E R

D

E INA RD

E CLOUD RD

E OLD VAIL RD

N C

AM

INO

DE

OES

TE

W DREXEL RD

E PRINCE RD

N CASA GRANDE HY

N HA

RR

ISON

RD

N H

AR

TMA

N L

N

N W

ILM

OT

RD

N SH

AN

NO

N R

D

N FL

OW

ING

WEL

LS R

D

N 1S

T AV

N C

AM

INO

DE

OES

TE

ÜH

igh

Low

Foothills: High Water Use

Central and Southern Tucson: Lower Water Use

Average Per-Capita Daily Water Use in Subdivision (GPCD)

Water UseGPCD

< 50.0

50.1 - 75.0

75.1 - 100.0

100.1 - 150.0

150.1 - 200.0

200.1 - 300.0

> 300.1

E I10

W I10N I1

9S

I19

N O

RA

CLE

RD

W AJO HY

E 22ND ST

W INA RD

E SPEEDWAY BL

E BROADWAY BL

S M

ISSI

ON

RD

N SILVERBELL RD

E VALENCIA RD

S K

OLB

RD

S H

OU

GH

TON

RD

W TANGERINE RD

N S

WA

N R

D

E GRANT RD

S PA

RK

AV

W I10 FRONTAGE RD

N L

A C

AN

AD

A D

R

S 12

TH A

V

S NO

GA

LES HY

S 6T

H A

V

N CA

MPB

ELL

AV

N T

HO

RN

YDA

LE R

D

S W

ILM

OT

RD

N C

RAY

CR

OFT

RD

W MOORE RD

E SUNRISE DR

N L

A C

HO

LLA

BL

E OLD SPANISH TR

E TANQUE VERDE RD

W VALENCIA RD

W IRVINGTON RD

E AJO WYW BOPP RD

E 36TH ST

E DREXEL RD

N K

OLB

RD

E 29TH ST

E 6TH ST

E CATA

LINA H

Y

S KINNEY RD

E GOLF LINKS RD

S SW

AN

RD

N S

OLD

IER

TR

E IRVINGTON RD

N 6

TH A

V

W ORANGE GROVE RD

W STARR PASS BL

E 5TH ST

N KINNEY RD

N 1

ST A

V

W SUNSET RD

S FR

EEM

AN

RD

N W

AD

E R

D

E INA RD

E CLOUD RD

E OLD VAIL RD

N C

AM

INO

DE

OES

TE

W DREXEL RD

E PRINCE RD

N CASA GRANDE HY

N H

AR

RISO

N R

D

N H

AR

TMA

N L

N

N W

ILM

OT

RD

N S

HA

NN

ON

RD

N F

LOW

ING

WEL

LS R

D

N 1

ST A

V

N C

AM

INO

DE

OES

TE

ÜH

igh

Low

Foothills: High Water Use

Southern and Southwestern Tucson: Lower Water Use

Lower Per-Capita Water Use in Southern/Southwestern Tucson can be related to the Larger Household/Newer, More Efficient Homes

Average Property Value for Subdivision(USD)

Property ValueUSD

< 50000

500000 - 100000.0

100000.1 - 200000.0

200000.1 - 300000.0

300000.1 - 400000.0

400000.1 - 500000.0

> 500000.0

E I10

W I10N I1

9S

I19

N O

RA

CLE

RD

W AJO HY

E 22ND ST

W INA RD

E SPEEDWAY BL

E BROADWAY BL

S M

ISSI

ON

RD

N SILVERBELL RD

E VALENCIA RD

S K

OLB

RD

S H

OU

GH

TON

RD

W TANGERINE RD

N SW

AN

RD

E GRANT RD

S PA

RK

AV

W I10 FRONTAGE RD

N LA

CA

NA

DA

DR

S 12

TH A

V

S NO

GA

LES HY

S 6T

H A

V

N CA

MPB

ELL

AV

N T

HO

RN

YDA

LE R

D

S W

ILM

OT

RD

N C

RAY

CR

OFT

RD

W MOORE RD

E SUNRISE DR

N LA

CH

OLL

A B

L

E OLD SPANISH TR

E TANQUE VERDE RD

W VALENCIA RD

W IRVINGTON RD

E AJO WYW BOPP RD

E 36TH ST

E DREXEL RD

N K

OLB

RD

E 29TH ST

E 6TH ST

E CATA

LINA H

Y

S KINNEY RD

E GOLF LINKS RD

S SW

AN

RD

N S

OLD

IER

TR

E IRVINGTON RD

N 6T

H A

V

W ORANGE GROVE RD

W STARR PASS BL

E 5TH ST

N KINNEY RD

N 1S

T AV

W SUNSET RD

S FR

EEM

AN

RD

N W

AD

E R

D

E INA RD

E CLOUD RD

E OLD VAIL RD

N C

AM

INO

DE

OES

TE

W DREXEL RD

E PRINCE RD

N CASA GRANDE HY

N HA

RR

ISON

RD

N H

AR

TMA

N L

N

N W

ILM

OT

RD

N S

HA

NN

ON

RD

N F

LOW

ING

WEL

LS R

D

N 1S

T AV

N C

AM

INO

DE

OES

TE

ÜH

igh

Low

Property Area, Property Value and Water Use

y = 3E-05x + 6.7705R2 = 0.6747

0

10

20

30

40

50

60

0 500,000 1,000,000 1,500,000

Average Property Value (USD)

Ave

rage

Wat

er U

se (C

cf)

Before 2000

After 2000

Water use increasing with both parcel area and property valueBest Fit with

Logarithmic Line; Level off with increasing parcel area

Best Fit with Liner Line; Stronger Fit than Parcel Area

Variability of Water Use within a Subdivision

Mean: 5454 sq ft

SD: 941

77% of Homes are within this rangeSimilar Sized

Homes

Example: Newer Subdivision constructed since 2000

Water Use within a Subdivision

Findings of the StudyHousehold size:

Large: southern and southwestern Tucson (More People live in Newer and More Efficient Homes)

Average per-household water use: High: Foothills (often over 20 Ccf [15,000 gal/mo]) Low: Central, Southern and Southwestern Tucson, (often less

than 7.5 Ccf [~6000 gal/mo])Average per-capita water use:

High: Foothills (up to 300 GPCD) Low: Southern and Southwestern Tucson (sometimes less than

50 GPCD)Water use increases with both parcel area and property value. A stronger relationship between property value and water use. High variability in water use within a subdivision, even if the

subdivision is similar in parcel area and house size (~30 GPCD to 130 GPCD).

Questions, Contacts and ResourcesContacts

Aktisu Kimoto akitsu.kimoto@pima.govEvan Canfield evan.canfield@pima.govTom Arnold tom.arnold@tucsonaz.gov

City of Tucson – Pima County Water Studyhttp://tucsonpimawaterstudy.com/Report to be posted in next week or two